If you are using any of the UNIX computers like leland, cmgm, pmgm, mmlab, etc... then you will be dealing with UNIX files. All of the programs on these machines like to receive a UNIX file, analyze it, then send the results back to you as another UNIX file. So, in order to run almost any UNIX program, and view the results, you need to understand some basic UNIX commands.
However, there are some tricks to avoid using UNIX commands. Like using an X terminal interface like MacX, OpenWindows, or Motif.